The present invention relates to a ceramic chip antenna, and more particularly, to a ceramic chip antenna of a helix structure with application to a wireless communication system.
Ceramic chip antennas have been widely accepted as an antenna element in the field of wireless communications due to their compactness. Typically, as shown in FIG. 1, such ceramic chip antennas include a helical conductor of a single helix structure embedded by printing into a main body composed of a plurality of laminated ceramic sheets. The helical conductor comprises a plurality of first horizontal strip lines 4a and a plurality of second horizontal strip lines 4b, both of which are thickly printed on the ceramic sheets. The helical conductor further comprises a plurality of vertical strip lines 5a and 5b that are produced by filling via holes (formed in the ceramic sheets) with conductive material. First horizontal strip lines 4a, second horizontal strip lines 4b, and vertical strip lines 5a and 5b are electrically connected to form an integral structure.
However, this single helical conductor structure poses a problem in terms of bandwidth when applied to a wireless communication system. Ceramic chip antenna 100 in FIG. 1 does not meet the wideband frequency characteristics required by a typical wireless communication system such as a mobile phone, WLAN, Bluetooth etc.
Alternatively, a ceramic chip antenna as shown in FIG. 2A is often used to meet the required wideband frequency characteristics of wireless telecommunication systems. Ceramic chip antenna 200 in FIG. 2A includes two helical conductors 7 and 8, which have different axes of helical rotation A, B, respectively. The structure of ceramic chip antenna 200 is further described with reference to FIG. 2B. First helical conductor 7 is formed by electrically connecting a plurality of first horizontal strip lines 7a, which are thickly printed on first ceramic sheet 6a, a plurality of vertical strip lines 7b, which are produced by filling via holes (not shown) formed in second ceramic sheet 6b and third ceramic sheet 6c with conductive materials, and a plurality of second horizontal strip lines 7c, which are thickly printed on fourth ceramic sheet 6d. Similarly, second helical conductor 8 is formed by connecting a plurality of third horizontal strip lines 8a, which are thickly printed on first ceramic sheet 6a, a plurality of vertical strip lines 8b, which are produced by filling via holes (not shown) formed in second ceramic sheet 6b and third ceramic sheet 6c with conductive materials, and a plurality of fourth horizontal strip lines 8c, which are also thickly printed on fourth ceramic sheet 6d. Power supplying terminals 9 and 10 are formed on first ceramic sheet 6a. 
As explained above, horizontal strip lines 7a, 7c, 8a and 8c are thickly printed on first and fourth ceramic sheets 6a and 6d to form the two helical conductors, so that the structure of ceramic chip antenna 200 avoids complexity in manufacturing. However, two problems are encountered with ceramic chip antenna 200: the size of the antenna inevitably becomes large because helical conductors 7 and 8 have different axes of helical rotation A and B from each other; and the structure of the antenna becomes complicated as two power supplying terminals 9 and 10 must be provided.
Accordingly, a need in the art exists to provide a ceramic chip antenna with a simple structure, which can be manufactured in an efficient manner while meeting wideband frequency requirements.
Therefore, an object of the present invention is to provide a ceramic chip antenna meeting wideband frequency requirements and having a simple structure for efficient manufacturing.
In accordance with one aspect of the present invention, a ceramic chip antenna is provided that comprises a main body formed by laminating a plurality of ceramic sheets made of a ceramic dielectric material, first and second helical conductors formed inside the main body, and a power supply section coupled to the first and second helical conductors for supplying power thereto, wherein the first and second helical conductors have the same axis of helical rotation as viewed from the power supply section.